Related Stories

America's senior spies have offered up to the public a frightening litany of the threats facing the US - al-Qaeda, hackers, Russian militants, and Edward Snowden. But sceptics note that scaring senators is a good way intelligence agencies can keep up their budgets.

In the national security business, fewer problems means less money.

"You tend to get the best funding when things are at their worst," said Gary LaFree, University of Maryland professor of criminology and director of terrorism research group Start.

Counter-terrorism is a grim world of sobering statistics, and indeed it seems to be getting gloomier.

Across the world, the number of attacks attributed to terrorists and militants has gone up. In 2012 there were more than 8,000 terror attacks worldwide, according to Mr LaFree, up from about 5,000 in 1991.

“Start Quote

US-based extremists will likely continue to pose the most frequent threat”

End QuoteJames ClapperDirector of national intelligence

On Wednesday, America's spy chief described the threat in a statement to the US Senate intelligence committee.

"We face an enduring threat to US interests overseas," said James Clapper, the US director of national intelligence.

He was testifying on a report compiled by intelligence officials entitled Worldwide Threat Assessment of the US Intelligence Community.

The report described threats within cyber and counterintelligence, with detours on to mass atrocities, extreme weather, water shortages, and more. The BBC spoke to terrorism analysts and others about the highlights.

The al-Qaeda franchise

Mr Clapper said organisations such as al-Qaeda in the Arabian Peninsula pose a threat to US citizens - but most of the attacks attributed to the group hit people in South Asia, the Middle East and North Africa.

The attacks are more lethal than in the past. Militant groups such as Basque separatists ETA used to issue public warnings before they would strike.

"There used to be a common expression: 'terrorists want a lot of people watching, not a lot of people dead,'" Mr LaFree said. "These days, there is an interest in not only a lot of people watching - but also in a lot of people dead."

Cyber threat

In recent months the debate over electronic intelligence and cyberspace has focused on the electronic surveillance operations exposed in the secret National Security Agency (NSA) documents released by Edward Snowden, the former NSA contractor turned fugitive in Russia.

On Wednesday, Mr Clapper reminded his audience about other dangers - the threat of cyber-attacks from rogue elements.

"The likelihood of a destructive attack that deletes information or renders systems inoperable will increase," he said.

For people who follow security issues, this is a familiar warning.

"'It's the cyber-Pearl Harbor.' It's what you say when you want to protect your budget," said Camille Francois, a fellow at Harvard's Berkman Center for Internet and Society. "But does that mean the threat is over-rated? I don't know."

Enemies of the state

Clapper described Edward Snowden, shown last year in Moscow, as a threat to the US

Meanwhile, Mr Clapper lumped Mr Snowden in with transnational crime rings, for-profit hackers and foreign spies in his rogues gallery of US enemies.

"Trusted insiders with the intent to do harm can exploit their access to compromise vast amounts of sensitive and classified information as part of a personal ideology or at the direction of a foreign government," Mr Clapper said.

He meant Mr Snowden, of course, and some sceptics found the focus on his case jarring.

"It doesn't belong on the list," said Steven Aftergood, director of the Project on Government Secrecy at the Federation of American Scientists.

"It tells you something about how deeply wounded the intelligence community was that they would even mention the Snowden documents in the same breath as the global threats."

Militants at home

Mr Clapper also warned of what he called "home-grown violent extremists" residing on US soil.

US officials have expressed concern about an estimated 70 Americans who went to Syria to fight in the civil war there - then came back. Officials have set up "costly round-the-clock surveillance" on them, said FBI Director James Comey, according to Time magazine.

Richard Barrett, formerly of MI6 and now a senior vice-president with private intelligence firm Soufan Group, said he was not sure the Americans who fought in Syria are that dangerous or that the threat justifies a major surveillance operation.

"I don't think they're doing all this just for the fun of it," he said. "But it's a huge amount of work to possibly stop a potential attack - all that surveillance, the whole thing."

He said this approach raised questions. First, "are you prepared to accept an element of risk? You can't have zero."

Secondly, he said, a more focused approach is usually more effective - namely relying on people who live in local communities to look out for militants and to help disrupt potential attacks.

"I think you're better protected with that than if you have a whole system of surveillance," he said.

Sochi and militant groups

In addition the report draws attention to the dangers that Americans may face next month at the Winter Olympics in Sochi, Russia.

"We have seen an increase in threat reporting just prior to the Olympics," said Mr Clapper.

In the end, though, it is not clear how much weight Mr Clapper's report has.

Critics of the Obama administration say the spy chiefs have discredited themselves. Mr Clapper has been accused of making misstatements to Congress if not outright lying, as the Washington Post reported.

The raw material

Marc Sageman, the author of Leaderless Jihad, on militant networks, discounted the value of the report, which he had not read. Its authors, he said, have misled the public in the past.

And he challenged the officials who prepared the report to make public the raw intelligence undergirding it.

BBC links

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.